首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   620篇
  免费   37篇
  国内免费   1篇
耳鼻咽喉   2篇
儿科学   15篇
妇产科学   13篇
基础医学   46篇
口腔科学   21篇
临床医学   107篇
内科学   145篇
皮肤病学   37篇
神经病学   11篇
特种医学   87篇
外国民族医学   1篇
外科学   47篇
综合类   37篇
预防医学   20篇
眼科学   2篇
药学   41篇
中国医学   1篇
肿瘤学   25篇
  2022年   14篇
  2021年   13篇
  2020年   9篇
  2019年   13篇
  2018年   15篇
  2017年   11篇
  2016年   9篇
  2015年   15篇
  2014年   19篇
  2013年   20篇
  2012年   8篇
  2011年   14篇
  2010年   32篇
  2009年   28篇
  2008年   9篇
  2007年   11篇
  2006年   13篇
  2005年   6篇
  2004年   6篇
  2003年   9篇
  2002年   6篇
  1999年   7篇
  1998年   21篇
  1997年   13篇
  1996年   24篇
  1995年   18篇
  1994年   25篇
  1993年   28篇
  1992年   13篇
  1991年   6篇
  1989年   17篇
  1988年   14篇
  1987年   8篇
  1986年   8篇
  1985年   14篇
  1983年   9篇
  1982年   10篇
  1981年   9篇
  1980年   11篇
  1979年   11篇
  1978年   7篇
  1977年   8篇
  1976年   6篇
  1975年   6篇
  1957年   9篇
  1956年   5篇
  1955年   7篇
  1954年   6篇
  1949年   8篇
  1948年   8篇
排序方式: 共有658条查询结果,搜索用时 203 毫秒
21.
Purpose: The aim of this study was to compare between the effects of resilient liner and clip attachments of bar‐implant‐retained mandibular overdenture on peri‐implant tissues. Materials and methods: In a randomized‐controlled clinical trial, 30 edentulous male patients (mean age 62.5 years) were equally assigned to two groups. In each patient, two implants were inserted in the canine area of the mandible using a two‐stage surgical protocol. After 3 months, the implants were connected with resilient bars. Mandibular overdentures were retained to the bars with either clips (group I) or silicone‐resilient liners (group II). Peri‐implant tissues were evaluated clinically (with regard to plaque scores, gingival scores and probing depths) and radiographically (with regard to peri‐implant vertical and horizontal alveolar bone changes). Evaluations were performed at the time of overdenture insertion (T0), 6 months (T6) and 12 months (T12) after overdenture insertion. Results: After 12 months of using bar‐implant‐retained mandibular overdenture, the resilient liner attachment had significantly decreased peri‐implant plaque score, gingival score, probing depth, vertical and horizontal bone loss when compared with the clip attachment. Conclusion: Within the limitations of this study, and in terms of peri‐implant tissue health of bar‐implant‐retained mandibular overdenture, we recommend resilient liner rather than clip attachment. To cite this article:
Elsyad MA, EL Shoukouki AH. Resilient liner vs. clip attachment effect on peri‐implant tissues of bar‐implant‐retained mandibular overdenture: a 1‐year clinical and radiographical study.
Clin. Oral Impl. Res. 21 , 2010; 473–480
doi: 10.1111/j.1600‐0501.2009.01879.x  相似文献   
22.
Loss-of-function variants in ANKRD11 were identified as the cause of KBG syndrome, an autosomal dominant syndrome with specific dental, neurobehavioural, craniofacial and skeletal anomalies. We present the largest cohort of KBG syndrome cases confirmed by ANKRD11 variants reported so far, consisting of 20 patients from 13 families. Sixteen patients were molecularly diagnosed by Sanger sequencing of ANKRD11, one familial case and three sporadic patients were diagnosed through whole-exome sequencing and one patient was identified through genomewide array analysis. All patients were evaluated by a clinical geneticist. Detailed orofacial phenotyping, including orthodontic evaluation, intra-oral photographs and orthopantomograms, was performed in 10 patients and revealed besides the hallmark feature of macrodontia of central upper incisors, several additional dental anomalies as oligodontia, talon cusps and macrodontia of other teeth. Three-dimensional (3D) stereophotogrammetry was performed in 14 patients and 3D analysis of patients compared with controls showed consistent facial dysmorphisms comprising a bulbous nasal tip, upturned nose with a broad base and a round or triangular face. Many patients exhibited neurobehavioural problems, such as autism spectrum disorder or hyperactivity. One-third of patients presented with (conductive) hearing loss. Congenital heart defects, velopharyngeal insufficiency and hip anomalies were less frequent. On the basis of our observations, we recommend cardiac assessment in children and regular hearing tests in all individuals with a molecular diagnosis of KBG syndrome. As ANKRD11 is a relatively common gene in which sequence variants have been identified in individuals with neurodevelopmental disorders, it seems an important contributor to the aetiology of both sporadic and familial cases.  相似文献   
23.
A facile single-step synthesis was performed to cross-link chitosan with thiocarbohydrazide to yield thiocarbohydrazide-chitosan (TC-Cht) which was for the first time evaluated as an inhibitor for corrosion of stainless steel in 3.5% NaCl solution. A comprehensive electrochemical analysis employing electrochemical impedance spectroscopy (EIS), potentiodynamic polarization (PDP), and cyclic voltammetry (CV) was undertaken and showed that the TC-Cht acts by adsorption on the steel surface and exhibits mixed type behavior with predominantly cathodic nature. The adsorption of TC-Cht molecules on the surface of stainless steel followed the Langmuir isotherm. The TC-Cht showed a high inhibition efficiency of >94% at 500 mg L?1 concentration. Surface investigation using SEM and EDX supported the inhibitor adsorption on the steel surface.  相似文献   
24.
25.
26.
27.
Menzel  T; Rahman  Z; Calleja  E; White  K; Wilson  EL; Wieder  R; Gabrilove  J 《Blood》1996,87(3):1056-1063
Chronic lymphocytic leukemia (CLL) is characterized by delayed senescence and slow accumulation of monoclonal, small lymphocytes. Basic fibroblast growth factor (bFGF) is a pleiotropic cytokine that plays a role in hematopoiesis and apoptosis. Elevated bFGF levels have been detected in urine from patients with a variety of neoplastic diseases including various leukemias; however, the cellular source of the bFGF has not been determined. In this study, the intracellular bFGF level in lymphocytes of 36 patients with B-CLL and 15 normal donors was determined using an enzyme-linked immunoassay. In cells derived from patients with high-risk disease, the median level of intracellular bFGF was 381.5 pg/2 x 10(5) cells, compared with a median of 90.5 pg/2 x 10(5) cells in patients with intermediate disease. In patients with low- risk disease, the median bFGF level was 4.9 pg/2 x 10(5) cells, and in normal controls, it was 6.0 pg/2 x 10(5) cells. The difference in the bFGF levels was significant for the comparison between low- and intermediate-risk (P = .00119), low- and high-risk (P < .0001), and intermediate- and high-risk disease (P = .0001). Immunofluorescent stains of peripheral blood mononuclear cells confirmed CLL lymphocytes as a cellular source of bFGF. To evaluate the potential contribution of elevated intracellular bFGF levels to the phenotype of CLL cells, leukemic cells were cultured in vitro with an apoptotic stimulus (fludarabine). CLL cells with high intracellular levels of bFGF appeared to be more resistant to fludarabine treatment. The addition of bFGF to fludarabine-treated CLL cells resulted in a delay of apoptosis and prolonged survival. These data suggest that bFGF may contribute to the resistance of CLL cells to an apoptotic stimulus.  相似文献   
28.

Objective

To assess the outcomes of the “hybrid” approach to chronic total occlusion (CTO) percutaneous coronary interventions (PCIs).

Background

The “hybrid approach” to CTO PCI advocates appropriate and early change of crossing strategy to maximize success, safety, and efficiency.

Methods

We prospectively recorded and analyzed detailed step‐by‐step procedural data in 73 consecutive CTO PCI cases performed by a single operator between July 2011 and August 2012.

Results

Technical success was achieved in 66 of 73 cases (90.4%). Mean patient age was 65 ± 7 years, and 30% had prior coronary artery bypass surgery. Dual injection was used in 78%. The primary approach was retrograde in 9 cases (12.5%) and antegrade in 64 cases (87.5%), of whom 25 cases (39.1%) underwent retrograde attempt after failed antegrade approach. The initial crossing approach was successful in 40 cases (54.8%), but 32 cases (44%) required 3.6 ± 1.4 approach changes (range 2–7). Antegrade wire escalation, antegrade dissection/reentry, and retrograde crossing were utilized in 97.2%, 46.6%, and 46.6% of cases, respectively. Among successful cases, the final CTO crossing technique was antegrade wire escalation in 50.0%, antegrade dissection/reentry in 24.2%, and retrograde in 25.8%. The mean procedure time, fluoroscopy time, and air kerma radiation exposure until CTO crossing or stopping the procedure were 66 ± 55 minutes, 25 ± 23 minutes, and 2.3 ± 1.9 Gray, respectively. Three patients (4.1%) had a major complication.

Conclusion

In the “hybrid approach” to CTO PCI, changes in crossing strategy were needed in approximately half the cases, resulting in high success and low complication rates. (J Interven Cardiol 2014;27:36–43)
  相似文献   
29.

BACKGROUND

Malignant fibrous histiocytoma, a subtype of primary lung sarcoma is a very rare disease. It usually presents as a lung nodules and the final diagnosis is made by immunohistochemical studies.

METHODS

A 45-year-old patient presented with progressive dyspnea, dry cough and right shoulder pain. Chest X-ray revealed complete opacification of the right hemithorax. Chest computed tomography confirmed the presence of a heterogeneous lesion occupying the whole right hemithorax causing a mass effect on the trachea. Ultrasound guided biopsy was done and final pathology was suggestive of malignant fibrous histiocytoma.

CONCLUSION

Progressive dyspnea in young otherwise healthy patients should be investigated early on. In our case the presence of right shoulder pain indicates advance disease illustrated by the singular imaging findings.  相似文献   
30.
Mefenorex is an indirect sympathomimetic amine which acts as an anorectic drug and is used in combination with low diet to treat excess weight. The central nervous system (CNS) effects of mefenorex were assessed in a randomized, double-blind, three-way cross-over, placebo-controlled study involving nine healthy young male volunteers. They received either a single oral dose of mefenorex 80 mg (twice the recommended dose) or d-amphetamine sulfate 18 mg or a placebo at 1-week intervals. CNS pharmacodynamic measurements consisted of subjective evaluation (visual analogue scales and the Addiction Research Centre inventory (ARCI)), EEG, psychomotor performance and attention (tracking, simple and choice reaction times, tapping, continuous performance task, DSST, body sway) and memory (working memory and recall of a word list). d-Amphetamine produced a typical psychostimulant EEG profile (significant decrease in slow delta waves and increase in fast beta activities), significantly increased amphetamine, benzedrine and morphine–benzedrine scores of ARCI and significantly decreased body sway compared to placebo and mefenorex. A trend in favour of a stimulant effect occurred for all other parameters (particularly speed of reaction) and no changes of memory were noticed. In contrast, mefenorex did not produce an amphetamine-like EEG profile, neither significantly changed ARCI scores nor significantly modified psychomotor and memory performance compared to the placebo, although it induced a decrease in body sway. In conclusion, the present results indicate that a single oral dose of mefenorex, at twice the recommended daily dose, does not possess amphetamine-like subjective and EEG stimulant effects or sensations of well-being, often encountered with drugs of abuse liability potential, in a healthy young population.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号